A193120 Number of n X n symmetric 0..3 arrays with each element equal to the sum mod 4 of two of its horizontal and vertical neighbors

0, 1, 17, 525, 60155, 26946822, 36060642759, 159137536303316, 2292846876178991797

Offset

1,3

Links

Table of n, a(n) for n=1..9.

Example

Some solutions for 4X4
..0..0..2..0....0..2..2..0....2..1..1..0....0..2..1..0....0..2..2..3
..0..0..2..2....2..1..3..2....1..3..2..3....2..2..1..3....2..1..3..1
..2..2..3..1....2..3..0..2....1..2..0..1....1..1..2..2....2..3..2..2
..0..2..1..2....0..2..2..0....0..3..1..2....0..3..2..0....3..1..2..0

Crossrefs

Sequence in context: A012232 A114063 A214135 * A264858 A112716 A218351

Adjacent sequences: A193117 A193118 A193119 * A193121 A193122 A193123

Keyword

nonn

Author

R. H. Hardin Jul 16 2011

Status

approved